Deputy spoksman Adam Ereli said the department's number three official, Undersecretary for Political Affairs Nicholas Burns, expressed Washington's unhappiness during a visit to Russia last week.

"Undersecretary Burns, I think, made clear to the Russians our broad concerns over Iranian behavior and this sale in particular," Ereli told the department's daily briefing.

"We certainly don't feel that this is a sale that would serve the interests of us or the region," he said.

Ereli spoke after Moscow confirmed plans to sell Iran 29 TOR M1 mobile surface-to-air missile defence systems in a contract worth more than 700 million dollars (600 million euros).

"I think it's important to remember and underscore that Iran is a state sponsor of terror, they have engaged in actions that we think are hostile and unhelpful," the spokesman said.

"We view this proposed sale in that context."